Starscourge Radahn is another demigod Shardbearer, and while defeating him isn’t mandatory to progress through the game, this encounter is definitely worth experiencing.
Your mount is available during this boss fight and makes the encounter much easier. However, since summoning another player makes you unable to ride Torrent, summoning another player makes the fight harder instead.
Several NPC summon signs are scattered throughout the boss room. When those summons die, they can be re-summoned as many times as needed by looking for their summon sign again near one of the spectral banners.
While this boss fight is much harder if you decide to go for a personal challenge by not using any of the summon signs throughout the boss room, using them makes the fight straightforward. The first thing you should do as the encounter begins, is to mount up and start looking for NPC summon signs.
These summon signs look a lot like a message left by another player, but with some extra glow to tell them apart. Interacting with them will summon an NPC, and you can summon as many NPCs at once as there are summon signs. Additionally, one of the summon signs will also grant you the Casual Greeting gesture, which is just another reason to make use of them. Lastly, if any of your summons die, you can re-summon them by looking for their summon signs near one of the spectral banners.
Using those summon signs isn’t entirely safe, as Radahn will be trying to punish you by using his bow. The arrows that he uses are faster than normal, and running sideways will not be enough to dodge them. Instead,if you’re on foot, you will have to dodge roll to avoid them, and if you’re riding Torrent you’ll have to use its dash while running sideways to avoid taking damage, as you would with a regular roll.
Those summons will immediately start going for Radahn, which will make him put away his bow for the remainder of the fight. While these NPCs will not be doing a lot of damage to the boss, the fact that you can re-summon them as many times as you like means that you can let them do the heavy lifting if you like. It may take a long time for the summons to defeat Radahn, but they will be able to take him down after being re-summoned many times. We can however speed it up by participating in the fight ourselves, which should be relatively safe to do while remaining mounted.
If you’re melee, the safest way to approach the fight is to let your summons distract the boss and wait for the end of one of his attacks/attack chains to go in for a hit, and then run out. While there may not be many openings to go in, you’ll be able to safely punish the boss if you remain patient. Additionally, inflicting the Poison or Scarlet Rot status effects on the boss will allow you to deal damage while waiting for an opening.
If you’re ranged, all you have to do is stay far enough away from the boss to be safe but close enough for your spells/ranged attacks to be able to reach him. If you stand far enough for your ranged attacks to barely reach him, you’ll always have plenty of time to react when the boss goes for you instead of your summons.
Starscourge Radahn‘s melee attacks shouldn’t pose much of a threat since you can mostly run away from them, but whether you’re melee or ranged, there are a handful of attacks that can still reach you if you’re not careful. Once Phase 2 begins especially, Radahn will start using more deadly Gravity attacks.
Gravity Wave:Radahn sends a wide wave forward along the ground, can be dodged by double jumping while riding Torrent or with a dodge roll.
Homing Stars: The boss summons several projectiles that fly towards their target. Can be dodged with well timed rolls, or by being mounted and taking sharp turns while sprinting.
Gravity Pull: Purple area of effect that pulls anything in its vicinity towards Radahn. Can be dodged with a well timed roll, or by running away whenever Radahn is glowing purple.
Gravity Boulders:Radahn pulls out 4 boulders out of the ground that start floating above him. Upon executing an attack chain that ends in a leap forward that can be followed by a Gravity Wave, the boulders fly towards the boss’s target, with a small delay. You need to start dodging as soon as the boss jumps up, as the boulders will fly towards you during the leap’s delay.
Comet Crash: Under 50% health, Starscourge Radahn jumps high enough to reach space. After a small delay, Radahn flies back down and crashes into a fiery explosion. This inflicts heavy damage, and begins Phase 2. Once the boss disappears, keep your eyes to the sky to see him crashing down, and just run away to avoid the explosion. If you’re having trouble seeing where he’s flying from, crank up your audio to hear his fiery descent.
Once the boss is defeated, make sure to exhaust the dialogue with the nearby NPCs, and activate the nearby site of grace.